Sanding and polishing work using an electric or pneumatic machine faces many challenges. On curved and complicated surfaces the machine needs to be very agile and easy to turn, when again on big surfaces there is need to keep up high sanding pressure in a static manner for long periods. The operator should be able to easily change working grip between one-hand and two-hand modes to avoid static stress. This same requirement arises also from that sometimes the working space is so narrow that it enables working with only one hand, whereas on greater continuous surfaces use of two hands would be preferable.
Current handheld machines are often intended and adapted for either one-hand or two-hand use but seldom properly suit for both modes of operation.